(CNN) — Ibragim Todashev, a man shot dead early Wednesday by an FBI agent in Orlando, Florida, has been connected to a 2011 triple homicide in Waltham, Massachusetts, according to a source close to investigators.

And a law enforcement official told CNN’s Susan Candiotti that Todashev, who was acquainted with deceased Boston Marathon bombing suspect Tamerlan Tsarnaev, was “directly involved” in the 2011 killings.

Todashev was questioned overnight about those homicides and whether he played a role in the Boston bombings.

“During questioning, it became clear that he was involved in the murders,” said the official, who spoke on condition of anonymity.

There was a confrontation between Todashev and police during questioning, according to a second law enforcement official, which led to the shooting and Todashev’s death.

Todashev attacked the FBI agent who shot him after he had confessed to a direct role in the 2011 triple homicide in Waltham, Massachusetts, a federal law enforcement official with direct knowledge of the case told CNN on Wednesday.

Investigators are awaiting test results to determine whether Todashev’s DNA was found at the Massachusetts triple murder scene and whether DNA of Boston Marathon bombing suspect Tamerlan Tsarnaev — an acquaintance of Todashev — also was found there.